A print server needs a long time to process a job with a large number of pages and thus will be occupied by this job for the long time. During processing the job, the print server cannot accept any other jobs. In the prior art, if the print server receives a rush print job when processing the large-scale job, the print server will let the currently processed job pause and then process the rush job. Although the rush job can be processed by doing so, the output portions of the paused large-scale job will be dropped and wasted. Furthermore, if the paused job is a single-sided job, it can be resumed manually. However, the manual operation for the resumption is complicated and fallible. In addition, many special printing tasks, such as double-sided printing, mixed printing and one-by-one printing, cannot be processed in the prior art.